1. Field of the Invention
The invention relates to a piston pump for pumping a fluid, having an improved piston, which pump is used in particular in brake systems of vehicles.
2. Description of the Prior Art
Piston pumps are known from the prior art in various versions. Know piston pumps are used for instance in vehicle brake systems that make an active pressure buildup as a function of predetermined driving situations possible. Examples of such brake systems are ABS, ESP or traction control systems. The response performance and pressure buildup of such piston pumps must be quite good, so that a control intervention in the brake system can be made as fast as possible.
In the known piston pumps, pistons are used that implement a delivery of the fluid by the piston. On the one hand, at least one transverse bore and one longitudinal bore must be made in the piston. In addition, the known piston pumps have stepped pistons, for which a very complicated and expensive plunge grinding procedure is required. Thus the known pistons are quite expensive to produce and furthermore have a relatively high flow resistance, because of the deflection of the fluid from the transverse bore into the longitudinal bore.